Pulmonary Embolism

Fred or someone else please put this in English. My brother in law may or may not have just been diagnosed with this. He had an MRI and are awaiting someone (doctor or specialist) to read it. He is up in the Research Triangle area so I feel good if it is this.

Background: Pulmonary embolism (PE) is an extremely common and highly lethal condition that is a leading cause of death in all age groups. A good clinician actively seeks the diagnosis as soon as any suspicion of PE whatsoever is warranted, because prompt diagnosis and treatment can dramatically reduce the mortality rate and morbidity of the disease. Unfortunately, the diagnosis is missed more often than it is made, because PE often causes only vague and nonspecific symptoms.

The most sobering lessons about PE are those obtained from a careful study of the autopsy literature. Deep vein thrombosis (DVT) and PE are much more common than usually realized. Most patients with DVT develop PE and the majority of cases are unrecognized clinically. Untreated, approximately one third of patients who survive an initial PE die of a future embolic episode. This is true whether the initial embolism is small or large.

Most cases of PE are diagnosed at autopsy, and most who die of PE have not had any diagnostic workup or treatment of the disease. In most cases, the diagnosis has not even been considered, even when classic signs and symptoms are documented in the medical chart. Sadly, appropriate diagnostic and therapeutic management often is withheld even when the potential diagnosis of PE has been considered explicitly and documented in the chart.


Pathophysiology: Pulmonary thromboembolism is not a disease in and of itself. Rather, it is an often fatal complication of underlying venous thrombosis. Under normal conditions, microthrombi (tiny aggregates of red cells, platelets, and fibrin) are formed and lysed continually within the venous circulatory system. This dynamic equilibrium ensures local hemostasis in response to injury without permitting uncontrolled propagation of clot. Under pathological conditions, microthrombi may escape the normal fibrinolytic system to grow and propagate. PE occurs when these propagating clots break loose and embolize to block pulmonary blood vessels.

Thrombosis in the veins is triggered by venostasis, hypercoagulability, and vessel wall inflammation. These 3 underlying causes are known as the Virchow triad. All known clinical risk factors for DVT and PE have their basis in one or more elements of the triad.

Patients who have undergone gynecologic surgery, those with major trauma, and those with indwelling venous catheters may have DVTs that start at any location. For other patients, venous thrombosis most often involves the lower extremities and nearly always starts in the calf veins, which are involved in virtually 100% of all cases of symptomatic spontaneous lower extremity DVT. Although DVT starts in the calf veins, it already has propagated above the knee in 87% of symptomatic patients before the diagnosis is made.

Studies suggest that nearly every patient with thrombus in the upper leg or thigh will have a PE if a sensitive enough test is done to look for it. Current techniques allow us to demonstrate PE in 60-80% of these patients, even though about half have no clinical symptoms to suggest PE. Thrombus in the popliteal segment of the femoral vein (the segment behind the knee) is the cause of PE in more than 60% of cases.

PE can arise from DVT anywhere in the body. Fatal PE often results from thrombus that originates in the axillary or subclavian veins (deep veins of the arm or shoulder) or in veins of the pelvis. Thrombus that forms around indwelling central venous catheters is a common cause of fatal PE.

The belief that calf vein DVT is only a minor threat is outdated and inaccurate. DVT of the calf is a significant source of PE and often causes serious morbidity or death. In fact, one third of the cases of massive PE have their only identified source in the veins of the calf. One important autopsy study showed that more than 35% of patients who died from PE had isolated calf vein thrombosis. Other studies have shown that the overall frequency of PE from DVT isolated to the small deep veins of the calf is 33-46%. Most of the time, emboli from calf veins are of smaller caliber than those from more proximal venous segments, but not all emboli from calf veins are small. Even a very narrow vein can produce a long, sinuous clot that can cause hemodynamic collapse, and approximately 40% of PEs from calf veins produce perfusion scan defects that are large or massive.

Calf emboli that are very small carry their own special risks. In a 1993 study of patients with identifiable thrombi causing paradoxical embolization through a patent foramen ovale, the source was isolated to the calf veins in 15 of 24 cases.

 

What part do you have a problem with?

A PE is basically a blood clot that goes to the lung. The prognosis is not good, but if he is already at a hospital, his chances are good that they can dissolve it with IV Heparin. If they live more than a few seconds, it probably is not a big one.

In 92, I was giving a girl who was 6 months pregnant her bedtime meds at Broughton. She grabbed my hand, gasped one time and dropped. She was dead before she hit the floor. IF a PE is gonna be fatal, it's usually instant.

The piece above talks about a PE coming from the calf (leg) because that's where most clots develop and break loose from. From there, they travel to the right side of the heart which pumps it right to the lungs. The vessels in the lungs are very tiny and that's where they usually get trapped.

Again, if he is at the hospital and being treated, his chances are good.

 

He's not in the hospital yet. I talked to him about 45 minutes ago and he was at home. He went to a clinic first this afternoon after having cold like symptoms for a while. That and he had been out all day clearing a 2 acre lot he and his wife bought to build on in Orange county and hopefully overdid it. He said his side was hurting? Anyway the clinic XRay'd him and then sent him to either Duke (his wife is a pediatric Pharmacist there) or Memorial in Chapel Hill for the MRI. Evidently someone saw something. IMO whoever told him it could be a PE needs to either know what the fuck he is talking about or STFU. For whatever reason there wasn't a doctor to read the results and evaluate it. So BIL goes back tomorrow morning to find out what is what.
Thanks

 

They tell him it "may" be a PE and send him home?

Ohhhh k.

If his wife is a Pharmacist, I'm sure she has at least gotten a few aspirins in him by now just to be safe.

 

Tell me about it. I would have showed my ass and sent a taxi to get the doctor to read it. I am not going to sleep much tonight wondering the results.

 

Does he have any underlying reasons to have a PE?

Smoker
Long term immobility (doesnt sound like it if he was out on the yard all weekend)
Pregnant (obviously not)


Why did they send him out?

 

Phew. The doctor says he has no Embolism. The X-Rays were the one that raised eyebrows. Evidently they showed signs of some cyst or something and evidence of pneumonia. He had been coughing like a crazy man last week. I bet he pulled a muscle coughing so hard then went in and saw the funny stuff on the x-ray. He went in today for a blood workup and the doctors don't seem too concerned. Granted this is all with me here and them up in Chapel Hill. I'll be heading that way on Friday

 

Fred, whats the pretest probablilty of seeing pneumonia on xray and looking for PE?